Compress-Archive does not include hidden files/folders
Creating an Archive with Compress-Archive does not include hidden files of folders.
I would recommend to adapt the behavior of Windows internal compressed Zip functionality which is including hidden files by default.
Additional i would prefere a sidenote in the documentation of
Vincent Spanjaart commented
... of compress-archive (https://technet.microsoft.com/de-de/library/dn841358.aspx)